<?php
/**
 * Spyc -- A Simple PHP YAML Class
 * @version 0.2.3 -- 2006-02-04
 * @author Chris Wanstrath <chris@ozmm.org>
 * @link http://spyc.sourceforge.net/
 * @copyright Copyright 2005-2006 Chris Wanstrath
 * @license http://www.opensource.org/licenses/mit-license.php MIT License
 * @package Core
 */

/**
 * 载入 YAML（通常扩展名为 .yml.php） 文件的内容，返回分析结果
 *
 * load_yaml() 会自动使用缓存，只有当 YAML 文件被改变后，缓存才会更新。
 *
 * 关于 YAML 的详细信息,请参考 www.yaml.org 。
 *
 * 用法：
 * <code>
 * $data = load_yaml('myData.yaml');
 * </code>
 *
 * 注意：为了安全起见，不要使用 YAML 存储敏感信息，例如密码。或者将 YAML 文件的
 * 扩展名设置为 .yml.php，并且在每一个 YAML 文件开头加上 # <?php exit(); ?>：
 * <code>
 * # <?php exit(); ?>
 *
 * invoice: 34843
 * date   : 2001-01-23
 * bill-to: &id001
 * ......
 * </code>
 *
 * 这样可以确保即便浏览器直接访问该 .yml.php 文件，也无法看到内容。
 *
 * @param string $filename
 * @param boolean $cacheEnabled 是否缓存分析内容
 *
 * @return array
 */
function load_yaml($filename, $cacheEnabled = true)
{
    if ($cacheEnabled) {
        if (!file_exists($filename)) {
            FLEA::loadClass('FLEA_Exception_ExpectedFile');
            __THROW(new FLEA_Exception_ExpectedFile($filename));
            return false;
        }

        $arr = FLEA::getCache('yaml-' . $filename, filemtime($filename), false);
        if ($arr) { return $arr; }
    }

    $spyc =& FLEA::getSingleton('Spyc');

    $arr = $spyc->load($filename);
    if ($cacheEnabled) {
        FLEA::writeCache('yaml-' . $filename, $arr);
    }
    return $arr;
}

/**
 * A node, used by Spyc for parsing YAML.
 * @package Core
 */
class YAMLNode {
    /**#@+
    * @access public
    * @var string
    */
    var $parent;
    var $id;
    /**#@+*/
    /**
     * @access public
     * @var mixed
     */
    var $data;
    /**
     * @access public
     * @var int
     */
    var $indent;
    /**
     * @access public
     * @var bool
     */
    var $children = false;

    /**
     * The constructor assigns the node a unique ID.
     * @access public
     * @return void
     */
    function YAMLNode() {
        $this->id = uniqid('');
    }
}

/**
 * The Simple PHP YAML Class.
 *
 * This class can be used to read a YAML file and convert its contents
 * into a PHP array.  It currently supports a very limited subsection of
 * the YAML spec.
 *
 * Usage:
 * <code>
 *   $parser = new Spyc;
 *   $array  = $parser->load($file);
 * </code>
 * @package Core
 */
class Spyc {

    /**
     * Load YAML into a PHP array statically
     *
     * The load method, when supplied with a YAML stream (string or file),
     * will do its best to convert YAML in a file into a PHP array.  Pretty
     * simple.
     *  Usage:
     *  <code>
     *   $array = Spyc::YAMLLoad('lucky.yml');
     *   print_r($array);
     *  </code>
     * @access public
     * @return array
     * @param string $input Path of YAML file or string containing YAML
     */
    function YAMLLoad($input) {
        $spyc = new Spyc;
        return $spyc->load($input);
    }

    /**
     * Dump YAML from PHP array statically
     *
     * The dump method, when supplied with an array, will do its best
     * to convert the array into friendly YAML.  Pretty simple.  Feel free to
     * save the returned string as nothing.yml and pass it around.
     *
     * Oh, and you can decide how big the indent is and what the wordwrap
     * for folding is.  Pretty cool -- just pass in 'false' for either if
     * you want to use the default.
     *
     * Indent's default is 2 spaces, wordwrap's default is 40 characters.  And
     * you can turn off wordwrap by passing in 0.
     *
     * @access public
     * @return string
     * @param array $array PHP array
     * @param int $indent Pass in false to use the default, which is 2
     * @param int $wordwrap Pass in 0 for no wordwrap, false for default (40)
     */
    function YAMLDump($array,$indent = false,$wordwrap = false) {
        $spyc = new Spyc;
        return $spyc->dump($array,$indent,$wordwrap);
    }

    /**
     * Load YAML into a PHP array from an instantiated object
     *
     * The load method, when supplied with a YAML stream (string or file path),
     * will do its best to convert the YAML into a PHP array.  Pretty simple.
     *  Usage:
     *  <code>
     *   $parser = new Spyc;
     *   $array  = $parser->load('lucky.yml');
     *   print_r($array);
     *  </code>
     * @access public
     * @return array
     * @param string $input Path of YAML file or string containing YAML
     */
    function load($input) {
        // See what type of input we're talking about
        // If it's not a file, assume it's a string
        if (!empty($input) && (strpos($input, "\n") === false)
        && file_exists($input)) {
            $yaml = file($input);
        } else {
            $yaml = explode("\n",$input);
        }
        // Initiate some objects and values
        $base              = new YAMLNode;
        $base->indent      = 0;
        $this->_lastIndent = 0;
        $this->_lastNode   = $base->id;
        $this->_inBlock    = false;
        $this->_isInline   = false;

        foreach ($yaml as $linenum => $line) {
            $ifchk = trim($line);

            // If the line starts with a tab (instead of a space), throw a fit.
            if (preg_match('/^(\t)+(\w+)/', $line)) {
                $err = 'ERROR: Line '. ($linenum + 1) .' in your input YAML begins'.
                ' with a tab.  YAML only recognizes spaces.  Please reformat.';
                die($err);
            }

            if ($this->_inBlock === false && empty($ifchk)) {
                continue;
            } elseif ($this->_inBlock == true && empty($ifchk)) {
                $last =& $this->_allNodes[$this->_lastNode];
                $last->data[key($last->data)] .= "\n";
            } elseif ($ifchk{0} != '#' && substr($ifchk,0,3) != '---') {
                // Create a new node and get its indent
                $node         = new YAMLNode;
                $node->indent = $this->_getIndent($line);

                // Check where the node lies in the hierarchy
                if ($this->_lastIndent == $node->indent) {
                    // If we're in a block, add the text to the parent's data
                    if ($this->_inBlock === true) {
                        $parent =& $this->_allNodes[$this->_lastNode];
                        $parent->data[key($parent->data)] .= trim($line).$this->_blockEnd;
                    } else {
                        // The current node's parent is the same as the previous node's
                        if (isset($this->_allNodes[$this->_lastNode])) {
                            $node->parent = $this->_allNodes[$this->_lastNode]->parent;
                        }
                    }
                } elseif ($this->_lastIndent < $node->indent) {
                    if ($this->_inBlock === true) {
                        $parent =& $this->_allNodes[$this->_lastNode];
                        $parent->data[key($parent->data)] .= trim($line).$this->_blockEnd;
                    } elseif ($this->_inBlock === false) {
                        // The current node's parent is the previous node
                        $node->parent = $this->_lastNode;

                        // If the value of the last node's data was > or | we need to
                        // start blocking i.e. taking in all lines as a text value until
                        // we drop our indent.
                        $parent =& $this->_allNodes[$node->parent];
                        $this->_allNodes[$node->parent]->children = true;
                        if (is_array($parent->data)) {
                            $chk = $parent->data[key($parent->data)];
                            if ($chk === '>') {
                                $this->_inBlock  = true;
                                $this->_blockEnd = ' ';
                                $parent->data[key($parent->data)] =
                                str_replace('>','',$parent->data[key($parent->data)]);
                                $parent->data[key($parent->data)] .= trim($line).' ';
                                $this->_allNodes[$node->parent]->children = false;
                                $this->_lastIndent = $node->indent;
                            } elseif ($chk === '|') {
                                $this->_inBlock  = true;
                                $this->_blockEnd = "\n";
                                $parent->data[key($parent->data)] =
                                str_replace('|','',$parent->data[key($parent->data)]);
                                $parent->data[key($parent->data)] .= trim($line)."\n";
                                $this->_allNodes[$node->parent]->children = false;
                                $this->_lastIndent = $node->indent;
                            }
                        }
                    }
                } elseif ($this->_lastIndent > $node->indent) {
                    // Any block we had going is dead now
                    if ($this->_inBlock === true) {
                        $this->_inBlock = false;
                        if ($this->_blockEnd = "\n") {
                            $last =& $this->_allNodes[$this->_lastNode];
                            $last->data[key($last->data)] =
                            trim($last->data[key($last->data)]);
                        }
                    }

                    // We don't know the parent of the node so we have to find it
                    // foreach ($this->_allNodes as $n) {
                    foreach ($this->_indentSort[$node->indent] as $n) {
                        if ($n->indent == $node->indent) {
                            $node->parent = $n->parent;
                        }
                    }
                }

                if ($this->_inBlock === false) {
                    // Set these properties with information from our current node
                    $this->_lastIndent = $node->indent;
                    // Set the last node
                    $this->_lastNode = $node->id;
                    // Parse the YAML line and return its data
                    $node->data = $this->_parseLine($line);
                    // Add the node to the master list
                    $this->_allNodes[$node->id] = $node;
                    // Add a reference to the node in an indent array
                    $this->_indentSort[$node->indent][] =& $this->_allNodes[$node->id];
                    // Add a reference to the node in a References array if this node
                    // has a YAML reference in it.
                    if (
                    ( (is_array($node->data)) &&
                    isset($node->data[key($node->data)]) &&
                    (!is_array($node->data[key($node->data)])) )
                    &&
                    ( (preg_match('/^&([^ ]+)/',$node->data[key($node->data)]))
                    ||
                    (preg_match('/^\*([^ ]+)/',$node->data[key($node->data)])) )
                    ) {
                        $this->_haveRefs[] =& $this->_allNodes[$node->id];
                    } elseif (
                    ( (is_array($node->data)) &&
                    isset($node->data[key($node->data)]) &&
                    (is_array($node->data[key($node->data)])) )
                    ) {
                        // Incomplete reference making code.  Ugly, needs cleaned up.
                        foreach ($node->data[key($node->data)] as $d) {
                            if ( !is_array($d) &&
                            ( (preg_match('/^&([^ ]+)/',$d))
                            ||
                            (preg_match('/^\*([^ ]+)/',$d)) )
                            ) {
                                $this->_haveRefs[] =& $this->_allNodes[$node->id];
                            }
                        }
                    }
                }
            }
        }
        unset($node);

        // Here we travel through node-space and pick out references (& and *)
        $this->_linkReferences();

        // Build the PHP array out of node-space
        $trunk = $this->_buildArray();
        return $trunk;
    }

    /**
     * Dump PHP array to YAML
     *
     * The dump method, when supplied with an array, will do its best
     * to convert the array into friendly YAML.  Pretty simple.  Feel free to
     * save the returned string as tasteful.yml and pass it around.
     *
     * Oh, and you can decide how big the indent is and what the wordwrap
     * for folding is.  Pretty cool -- just pass in 'false' for either if
     * you want to use the default.
     *
     * Indent's default is 2 spaces, wordwrap's default is 40 characters.  And
     * you can turn off wordwrap by passing in 0.
     *
     * @access public
     * @return string
     * @param array $array PHP array
     * @param int $indent Pass in false to use the default, which is 2
     * @param int $wordwrap Pass in 0 for no wordwrap, false for default (40)
     */
    function dump($array,$indent = false,$wordwrap = false) {
        // Dumps to some very clean YAML.  We'll have to add some more features
        // and options soon.  And better support for folding.

        // New features and options.
        if ($indent === false or !is_numeric($indent)) {
            $this->_dumpIndent = 2;
        } else {
            $this->_dumpIndent = $indent;
        }

        if ($wordwrap === false or !is_numeric($wordwrap)) {
            $this->_dumpWordWrap = 40;
        } else {
            $this->_dumpWordWrap = $wordwrap;
        }

        // New YAML document
        $string = "---\n";

        // Start at the base of the array and move through it.
        foreach ($array as $key => $value) {
            $string .= $this->_yamlize($key,$value,0);
        }
        return $string;
    }

    /**** Private Properties ****/

    /**#@+
    * @access private
    * @var mixed
    */
    var $_haveRefs;
    var $_allNodes;
    var $_lastIndent;
    var $_lastNode;
    var $_inBlock;
    var $_isInline;
    var $_dumpIndent;
    var $_dumpWordWrap;
    /**#@+*/

    /**** Private Methods ****/

    /**
     * Attempts to convert a key / value array item to YAML
     * @access private
     * @return string
     * @param $key The name of the key
     * @param $value The value of the item
     * @param $indent The indent of the current node
     */
    function _yamlize($key,$value,$indent) {
        if (is_array($value)) {
            // It has children.  What to do?
            // Make it the right kind of item
            $string = $this->_dumpNode($key,NULL,$indent);
            // Add the indent
            $indent += $this->_dumpIndent;
            // Yamlize the array
            $string .= $this->_yamlizeArray($value,$indent);
        } elseif (!is_array($value)) {
            // It doesn't have children.  Yip.
            $string = $this->_dumpNode($key,$value,$indent);
        }
        return $string;
    }

    /**
     * Attempts to convert an array to YAML
     * @access private
     * @return string
     * @param $array The array you want to convert
     * @param $indent The indent of the current level
     */
    function _yamlizeArray($array,$indent) {
        if (is_array($array)) {
            $string = '';
            foreach ($array as $key => $value) {
                $string .= $this->_yamlize($key,$value,$indent);
            }
            return $string;
        } else {
            return false;
        }
    }

    /**
     * Returns YAML from a key and a value
     * @access private
     * @return string
     * @param $key The name of the key
     * @param $value The value of the item
     * @param $indent The indent of the current node
     */
    function _dumpNode($key,$value,$indent) {
        // do some folding here, for blocks
        if (strpos($value,"\n")) {
            $value = $this->_doLiteralBlock($value,$indent);
        } else {
            $value  = $this->_doFolding($value,$indent);
        }

        $spaces = str_repeat(' ',$indent);

        if (is_int($key)) {
            // It's a sequence
            $string = $spaces.'- '.$value."\n";
        } else {
            // It's mapped
            $string = $spaces.$key.': '.$value."\n";
        }
        return $string;
    }

    /**
     * Creates a literal block for dumping
     * @access private
     * @return string
     * @param $value
     * @param $indent int The value of the indent
     */
    function _doLiteralBlock($value,$indent) {
        $exploded = explode("\n",$value);
        $newValue = '|';
        $indent  += $this->_dumpIndent;
        $spaces   = str_repeat(' ',$indent);
        foreach ($exploded as $line) {
            $newValue .= "\n" . $spaces . trim($line);
        }
        return $newValue;
    }

    /**
     * Folds a string of text, if necessary
     * @access private
     * @return string
     * @param $value The string you wish to fold
     */
    function _doFolding($value,$indent) {
        // Don't do anything if wordwrap is set to 0
        if ($this->_dumpWordWrap === 0) {
            return $value;
        }

        if (strlen($value) > $this->_dumpWordWrap) {
            $indent += $this->_dumpIndent;
            $indent = str_repeat(' ',$indent);
            $wrapped = wordwrap($value,$this->_dumpWordWrap,"\n$indent");
            $value   = ">\n".$indent.$wrapped;
        }
        return $value;
    }

    /* Methods used in loading */

    /**
     * Finds and returns the indentation of a YAML line
     * @access private
     * @return int
     * @param string $line A line from the YAML file
     */
    function _getIndent($line) {
        preg_match('/^\s{1,}/',$line,$match);
        if (!empty($match[0])) {
            $indent = substr_count($match[0],' ');
        } else {
            $indent = 0;
        }
        return $indent;
    }

    /**
     * Parses YAML code and returns an array for a node
     * @access private
     * @return array
     * @param string $line A line from the YAML file
     */
    function _parseLine($line) {
        $line = trim($line);

        $array = array();

        if (preg_match('/^-(.*):$/',$line)) {
            // It's a mapped sequence
            $key         = trim(substr(substr($line,1),0,-1));
            $array[$key] = '';
        } elseif ($line[0] == '-' && substr($line,0,3) != '---') {
            // It's a list item but not a new stream
            if (strlen($line) > 1) {
                $value   = trim(substr($line,1));
                // Set the type of the value.  Int, string, etc
                $value   = $this->_toType($value);
                $array[] = $value;
            } else {
                $array[] = array();
            }
        } elseif (preg_match('/^(.+):/',$line,$key)) {
            // It's a key/value pair most likely
            // If the key is in double quotes pull it out
            if (preg_match('/^(["\'](.*)["\'](\s)*:)/',$line,$matches)) {
                $value = trim(str_replace($matches[1],'',$line));
                $key   = $matches[2];
            } else {
                // Do some guesswork as to the key and the value
                $explode = explode(':',$line);
                $key     = trim($explode[0]);
                array_shift($explode);
                $value   = trim(implode(':',$explode));
            }

            // Set the type of the value.  Int, string, etc
            $value = $this->_toType($value);
            if (empty($key)) {
                $array[]     = $value;
            } else {
                $array[$key] = $value;
            }
        }
        return $array;
    }

    /**
     * Finds the type of the passed value, returns the value as the new type.
     * @access private
     * @param string $value
     * @return mixed
     */
    function _toType($value) {
        if (preg_match('/^("(.*)"|\'(.*)\')/',$value,$matches)) {
            $value = (string)preg_replace('/(\'\'|\\\\\')/',"'",end($matches));
            $value = preg_replace('/\\\\"/','"',$value);
        } elseif (preg_match('/^\\[(.+)\\]$/',$value,$matches)) {
            // Inline Sequence

            // Take out strings sequences and mappings
            $explode = $this->_inlineEscape($matches[1]);

            // Propogate value array
            $value  = array();
            foreach ($explode as $v) {
                $value[] = $this->_toType($v);
            }
        } elseif (strpos($value,': ')!==false && !preg_match('/^{(.+)/',$value)) {
            // It's a map
            $array = explode(': ',$value);
            $key   = trim($array[0]);
            array_shift($array);
            $value = trim(implode(': ',$array));
            $value = $this->_toType($value);
            $value = array($key => $value);
        } elseif (preg_match("/{(.+)}$/",$value,$matches)) {
            // Inline Mapping

            // Take out strings sequences and mappings
            $explode = $this->_inlineEscape($matches[1]);

            // Propogate value array
            $array = array();
            foreach ($explode as $v) {
                $array = $array + $this->_toType($v);
            }
            $value = $array;
        } elseif (strtolower($value) == 'null' or $value == '' or $value == '~') {
            $value = NULL;
        } elseif (ctype_digit($value)) {
            $value = (int)$value;
        } elseif (in_array(strtolower($value),
        array('true', 'on', '+', 'yes', 'y'))) {
            $value = TRUE;
        } elseif (in_array(strtolower($value),
        array('false', 'off', '-', 'no', 'n'))) {
            $value = FALSE;
        } elseif (is_numeric($value)) {
            $value = (float)$value;
        } else {
            // Just a normal string, right?
            $value = trim(preg_replace('/#(.+)$/','',$value));
        }

        return $value;
    }

    /**
     * Used in inlines to check for more inlines or quoted strings
     * @access private
     * @return array
     */
    function _inlineEscape($inline) {
        // There's gotta be a cleaner way to do this...
        // While pure sequences seem to be nesting just fine,
        // pure mappings and mappings with sequences inside can't go very
        // deep.  This needs to be fixed.

        // Check for strings
        $regex = '/(?:(")|(?:\'))((?(1)[^"]+|[^\']+))(?(1)"|\')/';
        if (preg_match_all($regex,$inline,$strings)) {
            $saved_strings[] = $strings[0][0];
            $inline  = preg_replace($regex,'YAMLString',$inline);
        }
        unset($regex);

        // Check for sequences
        if (preg_match_all('/\[(.+)\]/U',$inline,$seqs)) {
            $inline = preg_replace('/\[(.+)\]/U','YAMLSeq',$inline);
            $seqs   = $seqs[0];
        }

        // Check for mappings
        if (preg_match_all('/{(.+)}/U',$inline,$maps)) {
            $inline = preg_replace('/{(.+)}/U','YAMLMap',$inline);
            $maps   = $maps[0];
        }

        $explode = explode(', ',$inline);

        // Re-add the strings
        if (!empty($saved_strings)) {
            $i = 0;
            foreach ($explode as $key => $value) {
                if (strpos($value,'YAMLString')) {
                    $explode[$key] = str_replace('YAMLString',$saved_strings[$i],$value);
                    ++$i;
                }
            }
        }

        // Re-add the sequences
        if (!empty($seqs)) {
            $i = 0;
            foreach ($explode as $key => $value) {
                if (strpos($value,'YAMLSeq') !== false) {
                    $explode[$key] = str_replace('YAMLSeq',$seqs[$i],$value);
                    ++$i;
                }
            }
        }

        // Re-add the mappings
        if (!empty($maps)) {
            $i = 0;
            foreach ($explode as $key => $value) {
                if (strpos($value,'YAMLMap') !== false) {
                    $explode[$key] = str_replace('YAMLMap',$maps[$i],$value);
                    ++$i;
                }
            }
        }

        return $explode;
    }

    /**
     * Builds the PHP array from all the YAML nodes we've gathered
     * @access private
     * @return array
     */
    function _buildArray() {
        $trunk = array();

        if (!isset($this->_indentSort[0])) {
            return $trunk;
        }

        foreach ($this->_indentSort[0] as $n) {
            if (empty($n->parent)) {
                $this->_nodeArrayizeData($n);
                // Check for references and copy the needed data to complete them.
                $this->_makeReferences($n);
                // Merge our data with the big array we're building
                $trunk = $this->_array_kmerge($trunk,$n->data);
            }
        }

        return $trunk;
    }

    /**
     * Traverses node-space and sets references (& and *) accordingly
     * @access private
     * @return bool
     */
    function _linkReferences() {
        if (is_array($this->_haveRefs)) {
            foreach ($this->_haveRefs as $node) {
                if (!empty($node->data)) {
                    $key = key($node->data);
                    // If it's an array, don't check.
                    if (is_array($node->data[$key])) {
                        foreach ($node->data[$key] as $k => $v) {
                            $this->_linkRef($node,$key,$k,$v);
                        }
                    } else {
                        $this->_linkRef($node,$key);
                    }
                }
            }
        }
        return true;
    }

    function _linkRef(&$n,$key,$k = NULL,$v = NULL) {
        if (empty($k) && empty($v)) {
            // Look for &refs
            if (preg_match('/^&([^ ]+)/',$n->data[$key],$matches)) {
                // Flag the node so we know it's a reference
                $this->_allNodes[$n->id]->ref = substr($matches[0],1);
                $this->_allNodes[$n->id]->data[$key] =
                substr($n->data[$key],strlen($matches[0])+1);
                // Look for *refs
            } elseif (preg_match('/^\*([^ ]+)/',$n->data[$key],$matches)) {
                $ref = substr($matches[0],1);
                // Flag the node as having a reference
                $this->_allNodes[$n->id]->refKey =  $ref;
            }
        } elseif (!empty($k) && !empty($v)) {
            if (preg_match('/^&([^ ]+)/',$v,$matches)) {
                // Flag the node so we know it's a reference
                $this->_allNodes[$n->id]->ref = substr($matches[0],1);
                $this->_allNodes[$n->id]->data[$key][$k] =
                substr($v,strlen($matches[0])+1);
                // Look for *refs
            } elseif (preg_match('/^\*([^ ]+)/',$v,$matches)) {
                $ref = substr($matches[0],1);
                // Flag the node as having a reference
                $this->_allNodes[$n->id]->refKey =  $ref;
            }
        }
    }

    /**
     * Finds the children of a node and aids in the building of the PHP array
     * @access private
     * @param int $nid The id of the node whose children we're gathering
     * @return array
     */
    function _gatherChildren($nid) {
        $return = array();
        $node   =& $this->_allNodes[$nid];
        foreach ($this->_allNodes as $z) {
            if ($z->parent == $node->id) {
                // We found a child
                $this->_nodeArrayizeData($z);
                // Check for references
                $this->_makeReferences($z);
                // Merge with the big array we're returning
                // The big array being all the data of the children of our parent node
                $return = $this->_array_kmerge($return,$z->data);
            }
        }
        return $return;
    }

    /**
     * Turns a node's data and its children's data into a PHP array
     *
     * @access private
     * @param array $node The node which you want to arrayize
     * @return boolean
     */
    function _nodeArrayizeData(&$node) {
        if (is_array($node->data) && $node->children == true) {
            // This node has children, so we need to find them
            $childs = $this->_gatherChildren($node->id);
            // We've gathered all our children's data and are ready to use it
            $key = key($node->data);
            $key = empty($key) ? 0 : $key;
            // If it's an array, add to it of course
            if (is_array($node->data[$key])) {
                $node->data[$key] = $this->_array_kmerge($node->data[$key],$childs);
            } else {
                $node->data[$key] = $childs;
            }
        } elseif (!is_array($node->data) && $node->children == true) {
            // Same as above, find the children of this node
            $childs       = $this->_gatherChildren($node->id);
            $node->data   = array();
            $node->data[] = $childs;
        }

        // We edited $node by reference, so just return true
        return true;
    }

    /**
     * Traverses node-space and copies references to / from this object.
     * @access private
     * @param object $z A node whose references we wish to make real
     * @return bool
     */
    function _makeReferences(&$z) {
        // It is a reference
        if (isset($z->ref)) {
            $key                = key($z->data);
            // Copy the data to this object for easy retrieval later
            $this->ref[$z->ref] =& $z->data[$key];
            // It has a reference
        } elseif (isset($z->refKey)) {
            if (isset($this->ref[$z->refKey])) {
                $key           = key($z->data);
                // Copy the data from this object to make the node a real reference
                $z->data[$key] =& $this->ref[$z->refKey];
            }
        }
        return true;
    }


    /**
     * Merges arrays and maintains numeric keys.
     *
     * An ever-so-slightly modified version of the array_kmerge() function posted
     * to php.net by mail at nospam dot iaindooley dot com on 2004-04-08.
     *
     * http://us3.php.net/manual/en/function.array-merge.php#41394
     *
     * @access private
     * @param array $arr1
     * @param array $arr2
     * @return array
     */
    function _array_kmerge($arr1,$arr2) {
        if(!is_array($arr1))
        $arr1 = array();

        if(!is_array($arr2))
        $arr2 = array();

        $keys1 = array_keys($arr1);
        $keys2 = array_keys($arr2);
        $keys  = array_merge($keys1,$keys2);
        $vals1 = array_values($arr1);
        $vals2 = array_values($arr2);
        $vals  = array_merge($vals1,$vals2);
        $ret   = array();

        foreach($keys as $key) {
            list($unused,$val) = each($vals);
            // This is the good part!  If a key already exists, but it's part of a
            // sequence (an int), just keep addin numbers until we find a fresh one.
            if (isset($ret[$key]) and is_int($key)) {
                while (array_key_exists($key, $ret)) {
                    $key++;
                }
            }
            $ret[$key] = $val;
        }

        return $ret;
    }
}

